A computer network, such as the Internet, allows users to access information stored within one or more sites or servers associated with the network.
Certain networks, such as content delivery networks (CDN), provide for distribution of content to requesting users. A conventional CDN utilizes a group of servers, such as content delivery servers, for delivery of content from an originating content origin server to a requesting user. The CDN provides content to the requesting user, from a particular content delivery server, based on the relative distance between a content router (e.g., domain name server proxy) and the content delivery server. The distances can be based upon geography, network topology, network performance, or other metrics. A content delivery manager (CDM) associated with the CDN copies, or coordinates the copying of, the content from the originating content server to the content delivery servers within the CDN. Such servers are usually located at geographically distinct locations, although some locations can have multiple servers.
When a user device requests content (e.g., a Web page) from a content origin (e.g., origin server), certain mechanisms send the request, in accord with CDM-determined policy, to a suitable content delivery server within the CDN. A suitable server is defined as a server that is “close” to the content router servicing the requester in terms of the distances considered by the CDN. By sending the request to a server closer to the user device, the CDN provides relatively fast delivery of the content to the requesting user device. The CDN also acts to load balance multiple requests for content among the content delivery servers associated with the CDN to provide protection from large surges in traffic and overloading of a single content delivery server.
One conventional mechanism for sending a content request into the CDN involves the interception of the content request by a content router located in proximity to the origin server. For example, certain content routers, such as web cache control protocol (WCCP) enabled routers, are configured to intercept content requests sent toward an origin server and transmit the requests to a content server (e.g., a content server caching the requested content) in proximity (e.g., close) to the requesting user device.
Another conventional mechanism for sending a content request into the CDN involves explicit transmission of a request to a content delivery server, other than the origin server, within the CDN. For example, in a process known as non-transparent proxying, a requesting device browser is configured to send content requests, intended for an origin server, to a content server (e.g., a content server caching the requested content) within a CDN.
Another conventional mechanism for sending a content request into the CDN, for example, involves splitting or mirroring on a content server (e.g., content engine) located within the CDN, a website hosted by a host origin server. In such mirroring, the content server located within the CDN stores (e.g., caches) certain files or content associated with the website of the host origin server. The host origin server, for example, alters the content of the website, as stored by both the host origin server and the content server within the CDN, in order to distinguish the content (e.g., the content and the content locations) within a network. As the CDN receives requests for the content hosted by the origin server, the CDN transmits the content requests to the content server within the CDN.
In the case of conventional website splitting, the host origin server, for example, alters the content of the website, as stored by both the host origin server and the content server within the CDN, in order to distinguish the content (e.g., the content and the content locations) within a network. For example, after receiving a request for content from a content server within the CDN, the host origin server rewrites or renames the files or content to change the hostname associated with the content (e.g., renaming the file www.cars.com/photo.gif, as initially stored by the host origin server, into www.cars.newhost.com/photo.gif, to be stored by the content server within the CDN). In certain cases, the origin server renames multiple files or web pages that reference each other or include links to each other. In such a case, the host origin server rewrites the links of the renamed files. For example, requester engagement (e.g., clicking) of a link (e.g., Uniform Resource Locators or URL's) of a renamed web page served by the content server in the CDN sends the requester, via a DNS mechanism, to a subsequent web page served by the content server rather than by the host origin server. The host origin server then places (e.g., caches) the renamed files or content of a hosted website (e.g., the website hosted by the host origin server) on the requesting content server within the CDN.
Certain CDN content server providers, such as Akamai (Cambridge, Mass.) provide public CDN's having content servers for distribution of content originating from an origin server. Akamai CDN's have a load balancing device that intercepts content requests from a requesting device. The Akamai load balancing device uses a Domain Name Server (DNS) mechanism to direct the requesting device to an Akamai content server, within the CDN, having rewritten content from the origin server. During the renaming process, Akamai requires that origin servers rename the cached files or content in a particular Akamai format for storage on the Akamai servers. For example, requires rewriting of the link www.cars.com/foreign as http://www.akamai###.com/http:// www.cars.com/foreign in the Akamai format.